What 58mm UV 2A filter to Get?

I know this topic has been discussed on this forum in the past year, but I can't find the one mentioning brand or model numbers of UV 2A filters. Looking online at a multitude of uv filters, I can't verify which ones are 2a strength. Need for my panny 12-35 on E-M5 and E-M1.

Edit: the only one I can find that specifically mentions 2a is a Tiffen filter but I am not confident in the quality of this filter.